Golf clubs generally have three parts, the grip, the head, and the shaft that connects the grip to the head. The head, has a face designed to contact a golf ball. Each face has a sweet spot which is the most efficient portion of the face at transferring the force from the moving golf club to the ball.
Golf swings can be broken down into the following three parts. The address is when the golfer places the golf club behind the resting ball in a ready position to hit the ball. The backswing is when the golfer moves the club backward away from the ball, which mostly involves rotating the club around the golfer's body. The downswing is the movement of the club back to the ball, which mostly involves rotating the club in the opposite direction to the backswing.
The word “plane” was made popular by Ben Hogan many years ago. When viewed from the side of the golfer during the downswing, the plane is an invisible line on which the shaft of the club should travel toward the ball. For a baseball swing, that plane is basically parallel the ground. However, since the golf ball is resting on the ground, the club moves back into the ball at an angle to the ground and, thus, the swing plane is at an angle to the ground. The swing plane is optimally the same angle as the angle of the shaft during address. If the club is properly fitted to the golfer, the angle of the shaft during address will be the same as the lie angle of the club.
In most golf shots, the desired club shaft approach to the ball during the downswing is from the inside and then after contact the shaft moves again back inside, like a big gentle curve. While this movement sounds simple, the proper movement is not only very difficult to attain but also to retain.
U.S. Pat. No. 482,836 discloses a golf swing training device. This device uses rigid rails to align the head of a golf club during the swing. The use of such rigid rails provides a danger of causing damage to the golf club and/or golfer during a full golf swing. Furthermore, the rails do not provide a clear visual representation of the downswing golf shaft plane in either the vertical direction or the horizontal direction. The rails cannot be made narrower than the width of the club head, and in fact, must be far further apart than the width of the club head to allow the club head to move freely there between. Thus, this device cannot show the shaft plane, which is narrower than the width of the club head. Moreover, this device is large and cumbersome.
U.S. Pat. No. D407,773 discloses a golf club swing path and face angle measuring device. FIG. 2 shows a curved path the club head takes. The bristles extending from the base in a horizontal direction are sized and placed to direct the club head. Since the club head can rotate during the swing, directing the club head will not ensure that the club shaft is on the correct plane. Furthermore, the curved path of the bristles does not provide a clear visual representation of the downswing golf shaft plane in either the vertical direction or the horizontal direction.
U.S. Pat. No. 7,431,661 discloses a golf swing and putting trainer. The trainer includes rigid guides 31 and 32. While the rigid guides 31 and 32 can optionally be padded with foam, the use of such padded rigid rails provides a danger of causing damage to the golf club and/or golfer during a full golf swing. Furthermore, the use of rigid foam padded guides does not provide a clear visual representation of the downswing golf shaft plane in either the vertical direction or the horizontal direction. Moreover, since the guides are rigid, they must be placed far apart to ensure that the club does not contact them during use and the minimum distance between the guides is far larger than the length of a golf club head.
There are no known devices that can be used during a full swing to contact a ball so that the proper shaft plane can be quickly learned and grooved in. Furthermore, there are no known devices that are easily portable for use at any desired location, such as a golf range.